1. Field of the Invention
This invention relates to a mirror for use in combination with a lamp, and particularly, to a mirror made of a glass.
2. Description of the Prior Art
When a lamp is used in a various optical apparatus, a lamp only may be incorporated into an optical system in the optical apparatus in some cases, or a lamp assembly composed of a lamp, a mirror and other parts by securing of them with an adhesive or by another means may be incorporated into an optical system in the optical apparatus in some cases. The handling in the latter case is easier than that in the former case, and therefore, the lamp assembly has been used in a projector or a small-sized optical apparatus. The assembly, however, is generally provided with a positioning mechanism corresponding to a mechanism in the optical apparatus, because said assembly is required to be set in a predetermined position within said apparatus. FIG. 6 illustrates a lamp assembly comprising a double ended discharge lamp and a glass mirror, which are secured to each other with an adhesive. In this lamp assembly, the mirror 300 comprises a cylindrical portion 301 having a rectangular section, in which the one end of the discharge lamp 304 is secured with an adhesive 305, and an edge 302 having a projection 303. When this assembly is to be incorporated into and positioned in an optical apparatus, the cylindrical portion 301 and the projection 303 or the edge 302 are used for positioning. However, there are disadvantages that the handling of a covered wire 306 connected to the other end of the discharge lamp 304 is inconvenient and that the one end of the discharge lamp 304 is difficult to cool.